With so many amazing handpainted sock yarns around nowadays, it can be easy to overlook mass-produced sock yarns. There's a lot to be said for them, though: they're usually hardwearing, and the colours are well fixed. When what you want is a basic, hardworking solid, Cygnet Wool Rich 4Ply is as good as anything else. Because it's got a fairly high nylon content – 25% – it's probably not a good otion to wear against delicate skin. If you want a 4ply to knit into a Fair Isle cardigan, for example, opt for a yarn containing softer fibres, such as Merino wool or alpaca, but this is fine on the feet. The nylon makes the yarn hardwearing, so you won't be darning your socks after a couple of months' of wear.
I've been using the black colour (2066) as a contrast to handpainted yarns. Here it is knitted up into a pair of
Jack Sparrow's Favorite Socks (pattern from Katydid Knits):

It's best to use yarns of similar fibre content for a project like this, even if they're not the same brand, as they will wash and wear similarly. Some 4plies are bulkier than others, too, which could lead to sections of pattern being slightly raised above others.
I'm really pleased with this yarn; it's extremely good value for money and I'll definitely be buying more in the range for making everyday socks.
(Yes, sock blockers would make these socks look better!)